BIREFRINGENCE AND TILTED MODES IN ORDERED GAINP ALGAINP WAVE-GUIDES AND LASERS/

We have studied the influence of chemical ordering on the properties o f GaInP/AlGaInP optical waveguide structures and lasers. We have obser ved mode-conversion between transverse electric (TE) and transverse ma gnetic (TM) modes within typically 60 mu m. We show that an ordering-i nduced birefringence with the optical axis tilted with respect to the growth direction is responsible for the coupling of the TE and TM mode s. A new linear combination of TE and TM modes, the ''super modes,'' c an propagate in the waveguide without change. We show that these super modes govern the polarization of lasers made from ordered material. ( C) 1996 American Institute of Physics.